The invention relates to the treatment of neoplasms or other tumors as well as other diseases including hypercholesterolemia, autoimmune diseases, a viral diseases (e.g., hepatitis B, hepatitis C, or HIV), and diabetes.
Throughout the world there are public and government concerns about the increasing prevalence cancer. Many treatments exist but severe side effects and limited survival rate are pushing the research community into new approaches for treatments.
Cancer is a disease marked by the uncontrolled growth of abnormal cells. Cancer cells have overcome the barriers imposed on normal cells, which have a finite lifespan, to grow indefinitely. As the growth of cancer cells continue, genetic alterations may persist until the cancerous cell has manifested itself to pursue a more aggressive growth phenotype. If left untreated, metastasis, the spread of cancer cells to distant areas of the body by way of the lymph system or bloodstream, may ensue, destroying healthy tissue.
According to a recent American Cancer Society study, approximately 1,268,000 new cancer cases were expected to be diagnosed in the United States in the year 2001 alone. Lung cancer is the most common cancer-related cause of death among men and women, accounting for over 28% of all cancer-related deaths. It is the second most commonly occurring cancer among men and women; it has been estimated that there were more than 169,000 new cases of lung cancer in the U.S. in the year 2001, accounting for 13% of all new cancer diagnoses. While the rate of lung cancer cases is declining among men in the U.S., it continues to increase among women. According to the American Cancer Society, an estimated 157,400 Americans were expected to die due to lung cancer in 2001.
Cholesterol in Cell Membrane Activity
Cells require a flexible, permeable, fluid, active membrane. The cell membrane, which defines the cell and boundaries of cell organelles, is generally composed of lipid-cholesterol, phospholipids, sphingolipids, proteins, and carbohydrates. Cholesterol plays an important role in the flexibility, the fluidity, and the permeability of the membrane and the maintenance of these properties across a range of temperatures.
Cholesterol Synthesis and Uptake
Mammalian cells receive cholesterol through uptake of exogenic cholesterol and endogenous synthesis.
Exogenic uptake is mediated by specific receptors on the membrane itself; cholesterol is adsorbed from body fluids in contact with the cell. This uptake occurs through endocytosis of lipoprotein particles that contain cholesterol. The isomerization process of the phosphatidylcholine (FIG. 2) CC double bond cis/trans allow phospholipids with low density lipoprotein to contain specific receptors for cholesterol adsorption. Most animal cells acquire cholesterol by receptor-mediated endocytosis of low density lipoproteins that contain cholesterol to form endosomes which migrate to lysosomes for degradation and release of cholesterol into the cell.
By contrast, endogenous synthesis requires substantial energy. The synthesis of sterols (cholestane, vitamin D, and cholesterol) starts with squalene. Typically, cholesterol synthesis takes place in the cytoplasm of liver and intestinal cells through hydroxymethylglutaryl-CoA reductase (HMG-CoA reductase).
During the last three decades, cancer treatment was mainly focused on using cytotoxic products attacking both tumor and normal cells. There is therefore a need to finding additional targeted therapies to treat cancer with fewer side effects as compared to conventional therapies.